<template>
  <div id="app">
    <div>
      <span>全选:</span>
      <input type="checkbox" v-model="all" />
      <button @click="fx()">反选</button>
      <ul>
        <li v-for="item in arr" :key="item.name">
          <input type="checkbox" v-model="item.checked"/>
          <span>{{ item.name }}</span>
        </li>
      </ul>
    </div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      arr: [
        {
          name: '猪八戒',
          checked: false
        },
        {
          name: '孙悟空',
          checked: false
        },
        {
          name: '唐僧',
          checked: false
        },
        {
          name: '白龙马',
          checked: false
        }
      ]
    }
  },
  computed: {
    all: {
      get () {
        return this.arr.every(item => item.checked === true)        // 小框控制大框
      },
      set (value) {
        this.arr.forEach(item => (item.checked = value))
      }
    }
  },
  methods:{
    fx(){
      this.arr.forEach(item=>item.checked=!item.checked)
    }
  }
}
</script>

<style></style>
